It has been known that dl-tocopherols, particularly dl-.alpha.-tocopherol, can be synthesized, for example, by reacting isophytol with trimethylhydroquinone as shown in the following scheme. ##STR1##
It has been known that isophytol used as the starting material in this reaction can be synthesized according to the following scheme. ##STR2##
In the above method, isophytol, which is an important starting material for the production of dl-tocopherols, is synthesized from 6,10-dimethylundecan-2-one (C.sub.13 ketone) through many steps, in poor yield.